1. Field of the Invention
The present invention relates to an active matrix substrate including a matrix array of a plurality of pixels having a reflection electrode formed on a substrate, a reflection type liquid crystal display apparatus and a liquid crystal projector system using the same.
2. Description of the Related Art
The reflection type liquid crystal display apparatus is a known image display apparatus using an active matrix substrate and is widely used in liquid crystal projectors and reflection type liquid crystal displays (referred to as liquid crystal projector systems hereinafter), for example. The active matrix substrate used in the reflection type liquid crystal display apparatus has a matrix array of a plurality of pixels formed on a semiconductor substrate, such as a single-crystal silicon substrate, each of the pixels including a switching element and a pixel electrode having a reflective characteristic (referred to as a reflection electrode).
The active matrix substrate has a display region including a region in which pixels for displaying an image are arranged (referred to as an image display region hereinafter) and a region provided on the outer side of the image display region in which pixels provide only a black display (referred to as a black display region hereinafter). The active matrix substrate further has a region provided on the outer side of the image display region on the semiconductor substrate in which peripheral circuits, such as a vertical scanning circuit and a horizontal scanning circuit, are arranged (referred to as a peripheral circuit region). Japanese Patent Application Laid-Open No. 2006-267937 discusses improvement of the black display uniformity between the image display region and the black display region. To this end, according to the patent literature, the reflection electrodes in the image display region and the reflection electrodes in the black display region are arranged at substantially equal intervals, thereby improving the flatness between the image display region and the surrounding black display region. U.S. Pat. No. 5,990,988 discloses improvement of the panel flatness. To this end, according to the patent literature, the wiring layer between the switching elements and the reflection electrodes has a wiring pattern and a dummy pattern in a display region and a peripheral circuit region, thereby improving the precision of chemical mechanical polishing (CMP).